Folded dipole with end-loading elements

ABSTRACT

A combination Hertz and loop-type antenna which effectively receives both electromagnetic and waves of radio and TV broadcasts by virtue of oppositely extending elongated outer tubular conductors that concentrically surround an inner conductor and are held in annularly spaced relationship by conductive elements located near the ends of the conductors and insulating spacers medially thereof. The inner conductor is used to clamp onto a vertical mast by means of a clamp to thereby fix the antenna in a substantially horizontal position, and terminals are provided for connecting insulated output leads to the outer conductors adjacent their inner ends.

United States Patent [72] Inventor George Poliakoif Great Neck, N.Y.[21] Appl. No. 857,438 [22] Filed Sept. 12, 1969 [45] Patented Oct. 5,1971 [73] Assignee Aerial Electronics Corporation East Islip, NY.

[54] FOLDED DIPOLE WITH END-LOADING ELEMENTS 2 Claims, 2 Drawing Figs.

[52] US. Cl 343/792, 343/802, 343/803 [51] lnt.Cl H01g9/l6 [50] Field ofSearch 343/790, 791, 792, 803,908, 802

[56] References Cited UNITED STATES PATENTS 2.321.454 6/1943 Brown343/792 2,432,858 12/1947 Brown 343/792 3,001,194 9/1961 Leppert..343/792 3,210,765 10/1965 Jones 343/752 FOREIGN PATENTS 898,281 7/1944France 343/792 Primary Examiner-Eli Lieberman Attorney-Edward H. LovemanABSTRACT: A combination Hertz and loop-type antenna which effectivelyreceives both electromagnetic and waves of radio and TV broadcasts byvirtue of oppositely extending elongated outer tubular conductors thatconcentrically surround an inner conductor and are held in annularlyspaced relationship by conductive elements located near the ends of theconductors and insulating spacers medially thereof. The inner conductoris used to clamp onto a vertical mast by means of a clamp to thereby fixthe antenna in a substantially horizontal position, and terminals areprovided for connecting insulated output leads to the outer conductorsadjacent their inner ends.

PATENTEUHBI 5l97| 3.611.397

INVENTOR GEORGE POLIAKOFF ATTORNEY FOLDED DIPOLE WITH END-LOADINGELEMENTS This invention relates to antennas for receiving FM AM, and TVbroadcasts, and more particularly to a hybrid-type dipole-loop aerial.

When a radio wave is generated, there is produced in space an electricfield as well as an electromagnetic field. Such fields are at rightangles to each other and to the direction of wave propogation.Basically, there are two types of antennas in common use: (1) The Hertz,or dipole type; and (2) The loop type, used mostly in radio receivers.The dipole type of antenna is more sensitive to the electric field;while the loop type is more sensitive to electromagnetic fields. Whiledipole antennas, as well as loop-type aerials are well known, therepresently exists a real need for antennas that can receive TV as well asFM and AM radio broadcasts with equally high efiiciency on the sameantenna that is fixed to a mast.

Briefly, in accordance with the present invention, a hybrid antenna isprovided which, while having the appearance of a single dipole aerial,is in reality, a combination of both dipole type and a loop typeantenna. This is accomplished by the provision of an elongated innertubular conductor that is electrically and spacially fixed by aconnector located at each end thereof, to a pair of outer surroundingconcentric conductive arms. The connectors hold the outer ends of eacharm in spaced relationship and output leads are connected to the innerends of each of these arms which are spacially supported by insulatingspacers.

It is, therefore, a primary object of this invention to provide anantenna that combines the benefits of both a dipole and loop-typeantenna and being compact, simple in construction, light in weight,consisting of few parts, and which is easy to ship, pack and assemble.

Another object is to provide a novel hybrid antenna that can be used toreceive TV, FM and AM broadcasts with equal facility on the sameantenna.

These and other objects and many of the attendant advantagesof thisinvention will be readily appreciated as the same becomes clear byreference to the following detailed description when considered inconnection with the accompanying drawings, wherein FIG. 1 is aperspective view with parts broken away of a hybrid antenna of thepresent invention.

FIG. 2 is an enlarged cross-sectional view along line 22 of F IG. 1.

Referring now to the drawings, wherein like reference numerals designatelike parts throughout, there is shown in FIG. 1 an antenna embodying thepresent invention which includes two oppositely extending horizontaltubular conductor arms 12 which are axially aligned with one another.Within each of the outer arms 12 is a single inner conductor 14 ofrelatively small diameter. The outer tubular conductors 12 are held inspaced concentric relationship to inner conductor 14 by a member 17located adjacent each outer end of each of the arms 12 and by aninsulated spacer 16 located at each inner end of the conductors 12 asclearly illustrated in FIG. 2. The spacers 16 may be fastened to eitherthe inner conductor 14 or the outer conductor 12 or to both conductorsby any conventional means. A fastener (not shown) of nonconductivematerial may be used to secure the spacer 16 to the inner conductor 14.It is of course obvious that insulator spacer 16 may be secured betweenconductors 14 and 12 by other conventional means, i.e., adhesive, pressfit, etc. The member 17 may be a pin or any other conventional elementmade of an electrically conductive material. A clamp, which is connectedmedially to the ends of conductor 14, between the arms 12 is attached toa vertical mast l8. Terminals 22, comprising rising nuts, are providedadjacent the inner ends of the outer conductors for connecting outputleads 24, 24 thereto. Such leads are insulated from each other and passthrough the eye of a bracket 26 which is clamped to the mast 18 belowthe antenna 10.

Conventional capacitor disks 28 having central holes 29 for receivin theouter conductors, and are carried by the latter in arrays of three diskseach, with the disks 28 equally spaced in each array 30, and the arrayssymmetrically arranged with respect to each other on the outer reachesof the outer conductors. Such arrays may be omitted without departingfrom the present invention, if desired.

In operation, since the central or inner conductor 14 is electricallyconnected, at each end via connectors 17, to the points of maximumsignal voltage of the corresponding outer conductors, signal current iscaused to flow through the inner conductors 14 as well as out throughthe leads 24 to the receiver (not shown). Consequently, the antenna 10is neither a current nor a voltage antenna, nor is it a Hertzian, nor aloop antenna, but a combination of such types.

The outside diameter of the outer conductors l2, determines the bandwidth, while the ratios of the diameters of the outside conductors 12,to that of the inside conductor 14 determines the impedance of theantenna 10.

Inasmuch as the antenna of the present invention responds both toelectric and magnetic fields, it is as much a loop antenna as it is afolded dipole, but it is definitely not a plain dipole antenna becauseof the inner conductor. [f the inner conductor is left out, theperformance of the device is greatly impaired, and while in one respectit may be considered a folded dipole in the sense that the ends of theinner conductor are connected to the outer conductor, it is considerablymore than that, as evidenced by the performance of the antenna.

It should be understood that the foregoing disclosure relates to only apreferred embodiment of the invention and that it is intended to coverall changes and modification of the example of the invention hereinchosen for the purposes of the disclosure which do not constitutedepartures from the spirit and scope of the invention.

The invention claimed is:

l. A hybrid antenna comprising in combination:

a cylindrical inner conductor,

two tubular cylindrical outer conductors arranged in axial alignmentwith their respective inner ends spaced from each other, andconcentrically spaced around said inner conductor,

each of the respective outer ends of said outer conductors beingsubstantially in alignment with one of the outer ends of said innerconductor, insulating spacer means located between said inner conductorand each of the inner ends of said outer conductor to maintainconcentricity between said conductors,

electrically conductive members located near the outer ends of saidinner and outer conductors for completing an electric circuitthereinbetween and for securing said conductors in spaced relationshipwith each other, a plurality of capacitor disks located on each of saidouter conductors adjacent the remote ends thereof, and

means for connecting insulated output leads to the inner ends of saidouter conductors. 2. The invention as defined in claim 1 furthercomprising clamping means connected to said inner conductor, and avertical mast attached to said clamp whereby said antenna will beclamped to said mast with said conductors thereof extendingsubstantially at right angles to said mast.

1. A hybrid antenna comprising in combination: a cylindrical innerconductor, two tubular cylindrical outer conductors arranged in axialalignment with their respective inner ends spaced from each other, andconcentrically spaced around said inner conductor, each of therespective outer ends of said outer conductors being substantially inalignment with one of the outer ends of said inner conductor, insulatingspacer means located between said inner conductor and each of the innerends of said outer conductor to maintain concentricity between saidconductors, electrically conductive members located near the outer endsof said inner and outer conductors for completing an electric circuitthereinbetween and for securing said conductors in spaced relationshipwith each other, a plurality of capacitor disks located on each of saidouter conductors adjacent the remote ends thereof, and means forconnecting insulated output leads to the inner ends of said outerconductors.
 2. The invention as defined in claim 1 further comprisingclamping means connected to said inner conductor, and a vertical mastattached to said clamp whereby said antenna will be clamped to said mastwith said conductors thereof extending substantially at right angles tosaid mast.